1. Field of the Invention
This invention relates to a three-dimensional sheet block stacking system used for forming a predetermined number of stacked-sheet blocks (or stacks of sheet blocks) by stacking up a predetermined number of sheet blocks.
2. Description of the Prior Art
Example of the type of sheet blocks mentioned above include banknotes, lottery tickets, postcards, various kinds of tickets, etc. It is a common practice that these sheets are piled up and bound per unit of, for example, 100 sheets, then 10 of such piles of sheets are stacked up and bound to form a stacked-sheet block (or stack of sheet blocks) in series (1 to 1000), and are then delivered from a printing factory. This system or device for forming the stacked-sheet blocks is used after the process of printing and forming piles of sheets has been carried out. In order to satisfy the on-line working conditions between the two processes, the second process is required to be able to correspond in speed to the first process.
A conventional sheet block stacking system or device of this type has an intermittent rotary drum. A number of pocket groups for receiving the sheet blocks are arranged on the surface of the drum in a circular pattern as seen in plan view. The piles of sheets are inserted into the pockets of the drum in series. Then, the piles of sheets are gradually taken out of the pockets so as to be stacked up in series.
According to the above prior art, it is necessary for the workers to insert the piles of sheets temporarily into the pockets of the rotary drum in series and then take them out of the pockets so as to be stacked up. It takes much time and labor to change the arrangement of the pockets. It sometimes becomes necessary to prepare additional spare drum having a different arrangement. To this end, a storage space is required and therefore, the prior art is very inefficient and uneconomical. Particularly, it is actually impossible to form stacked-sheet blocks at the high speed required by today's high speed printing.